From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757603Ab0CKSeS (ORCPT ); Thu, 11 Mar 2010 13:34:18 -0500 Received: from hera.kernel.org ([140.211.167.34]:37117 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756328Ab0CKSeJ (ORCPT ); Thu, 11 Mar 2010 13:34:09 -0500 Date: Thu, 11 Mar 2010 18:33:22 GMT From: tip-bot for Mike Galbraith Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1268301675.6785.44.camel@marge.simson.net> References: <1268301675.6785.44.camel@marge.simson.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched: Remove ASYM_GRAN feature Message-ID: Git-Commit-ID: 13814d42e45dfbe845a0bbe5184565d9236896ae X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 11 Mar 2010 18:33:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 13814d42e45dfbe845a0bbe5184565d9236896ae Gitweb: http://git.kernel.org/tip/13814d42e45dfbe845a0bbe5184565d9236896ae Author: Mike Galbraith AuthorDate: Thu, 11 Mar 2010 17:17:04 +0100 Committer: Ingo Molnar CommitDate: Thu, 11 Mar 2010 18:32:53 +0100 sched: Remove ASYM_GRAN feature This features has been enabled for quite a while, after testing showed that easing preemption for light tasks was harmful to high priority threads. Remove the feature flag. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1268301675.6785.44.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 28 +++++++++++----------------- kernel/sched_features.h | 6 ------ 2 files changed, 11 insertions(+), 23 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 1d99535..9357ecd 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1583,24 +1583,18 @@ wakeup_gran(struct sched_entity *curr, struct sched_entity *se) /* * Since its curr running now, convert the gran from real-time * to virtual-time in his units. + * + * By using 'se' instead of 'curr' we penalize light tasks, so + * they get preempted easier. That is, if 'se' < 'curr' then + * the resulting gran will be larger, therefore penalizing the + * lighter, if otoh 'se' > 'curr' then the resulting gran will + * be smaller, again penalizing the lighter task. + * + * This is especially important for buddies when the leftmost + * task is higher priority than the buddy. */ - if (sched_feat(ASYM_GRAN)) { - /* - * By using 'se' instead of 'curr' we penalize light tasks, so - * they get preempted easier. That is, if 'se' < 'curr' then - * the resulting gran will be larger, therefore penalizing the - * lighter, if otoh 'se' > 'curr' then the resulting gran will - * be smaller, again penalizing the lighter task. - * - * This is especially important for buddies when the leftmost - * task is higher priority than the buddy. - */ - if (unlikely(se->load.weight != NICE_0_LOAD)) - gran = calc_delta_fair(gran, se); - } else { - if (unlikely(curr->load.weight != NICE_0_LOAD)) - gran = calc_delta_fair(gran, curr); - } + if (unlikely(se->load.weight != NICE_0_LOAD)) + gran = calc_delta_fair(gran, se); return gran; } diff --git a/kernel/sched_features.h b/kernel/sched_features.h index f54b6f9..83c66e8 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -17,12 +17,6 @@ SCHED_FEAT(START_DEBIT, 1) SCHED_FEAT(WAKEUP_PREEMPT, 1) /* - * When converting the wakeup granularity to virtual time, do it such - * that heavier tasks preempting a lighter task have an edge. - */ -SCHED_FEAT(ASYM_GRAN, 1) - -/* * Based on load and program behaviour, see if it makes sense to place * a newly woken task on the same cpu as the task that woke it -- * improve cache locality. Typically used with SYNC wakeups as